Flip-flop indicator



Sept. 27, 1960 E. H. BODEN FLIP-FLOP INDICATOR Filed June 8, 1959 INVENTOR ATTORNEY United States Patent FLIP-FLOP INDICATOR Evan H. Boden, Emporium, Pa., assign'or to Sylvania Electric Products Inc., a corporation of Delaware Filed June 8, 1959, Ser. No. 818,913

3 Claims. (Cl. 313-3) This invention relates to indicators built in with a tube having multiple electron streams to indicate the relative flow of these streams.

In particular the invention relates to electron tubes used in multivibrator or flip-flop circuits to indicate whether the tube is or is not conducting and to what extent.

Many multivibrator circuits employ multifunction tubes, such as double triodes, to alternately carry the current through one or the other of the triodes. It is often desirable to know which of the triodes is conducting at any given time.

It is the main object of this invention to provide a multifunction tube having multiple electron stream paths therein with individual indicators readily perceivable from the top of a tube which will function to indicate whether or not current is flowing or flowing heavily in a given path.

It is a further object of the invention to make the indicator as a simple component of the electron tube.

Also it is an object of the invention to place the indicators in such position and to make them of such form that they will readily indicate whether a tube section in a flip-flop circuit is or is not conducting.

Further objects will become apparent after consideration of the following description when taken in conjunction with the accompanying drawing in which:

Fig. 1 is a section through an electron tube incorporating the invention.

Fig. 2 is a section on the line 2-2 of Fig. 1.

Fig. 3 is an enlarged view of the upper end of the electrodes in Fig. 1.

Fig. 4 is a perspective view of the indicator electrode and Fig. 5 is a modification showing how an indicator supporting plate may be secured to an insulating spacer.

Referring to the drawing in greater detail, at 10 is the glass bulb of an electron tube through whose wafer base 12 extends the conventional electrode leads 14. For the purpose of this disclosure, the type of tube selected for modification is a conventional double triode, for example a 12AU7 electron tube, the same having indirectly heated emissively coated cathode sleeves 16 to form cathodes,

2,954,493 Patented Sept... 2.7, 196!) lower portion of the plate, is a lead wire 32, threaded through apertures in the upper and lower spacers and electrically connected integrally or otherwise with a lead in wire 34 in the base of the tube. To hold the plate in position, the lower edge thereof is provided with a pin 36 snugly fitting in a registering aperture in the spacer 22 and the wire 32 has welded thereto a tab 38 snugly en-. gaging the underface of the spacer 22. In Fig. 5 there is shown a modified form for holding the plate in place and wherein in lieu of the pin 36 and tab 38, the plate at its lower edge is provided with lugs 40 and 42 bent in opposite directions, as indicated, to tightly engage the. undersurface of the spacer 22.

Electrically bonded with the plate 30, as by welding, is an anode 44 having a cross section in the form of an inverted V, with opposing faces 46 and 48, coated with strips 50 of a phosphor, such as Willemite, and which will glow when bombarded by electrons. Although the anode, is here shown of inverted V form to render the glowing strips visible from various angles above and toward the sides of the tubes, it is possible to make the anode faces vertical.

The strips leave uncoated areas on the anode 44, on each face, above and below the strips so as to leave areas which will not glow when the anode is bombarded by electron streams.

The cathode sleeves 16 project above the spacer 22 and there they are additionally coated with the conventional alkaline earth triple carbonates 52, in the same manner as the cathode sleeve portions between the spacers 22 and 24. However the emissive material above the spacer 22 extends up only part way of the vertical height of the phosphor strips, preferably, up to its horizontal mid section. The anodes 20 and 21 have lugs as 54 which are bent over the spacers to maintain the parts secured together. A lug 56 on each anode on the side of the anode near the anode 44 is projected through the spacer 22 and is not bent over the spacer as are other lugs. To the lugs 56 are secured rectangular metallic electron stream de-' flecting plates 57 and 58, as by welding. Each plate 57 or 58 is of the width of anode 44 and of a height preferably to reach one third of the way up the phosphor strip.

The lead 34 is connected to a voltage source at least as high as the voltage on the anodes 20 and 21 when the sections are not conductive and preferably to a higher voltage. Thus if a voltage of 250 be applied to the anodes 20 and 21, it is preferable to apply a voltage of 300 to the lead 34 and the anode 44.

When the right hand tube section, Figure 3, is non-conducting, the plate voltage on anode 21 is at 250 volts and the voltage on anode 44 remains at 300. This results in a strong positive field about the plate 58 shading part of the electron stream so that the remaining portion of the stream strikes the anode 44 at an uncoated portion thereof and there will be no glow apparent on the anode 44 on that side of the electron tube. The stream will, in.

. effect, be entirely clear of the phosphor because of the cater to denote which side of the triode is conducting and to indicate at the same time the conductive state of the other triode.

To achieve this result, the double triode has been modified. Standing on edge atop the upper insulating spacer 22 is a rectangular electro-conductive plate 30. Electrically connected to the plate, as by a weld joint to the action of the plate 58. On the other hand, considering the left hand side of the tube as conducting, the voltage on the anode 20 will drop, as to 200 volts, and the field. surrounding the plate 57 will not be strong enough to deflect the electron stream from oif the phosphor. There-- fore, a glow will be visible on the left side of anode 44. If not in a flip-flop circuit, how much of the phosphor strips will be struck by the electron streams depends upon the voltages on the respective anodes. Thus it can be; ascertained from atop a tube not only which section of a. double tube is operating but to What degree.

What is claimed is:

1. An electron device having an insulating spacer, electrodes to provide for discrete streams of electrons and? 3 control electrodes to control the flow of said streams, said first electrodes including a pair of anodes below said spacer and a cathode for said anodes extending below and above said spacer, each of said anodes having a con: ductive element extending through said spacer, parallel plates above the spacer connected to said elements, a third anode positioned between and parallel to said plates presenting a face to each of said parallel plates and anelectron sensitive phosphor on each face, said phosphor being in the form of a strip extending parallel to the spacer andiof a height less than the height of the third anode to leave an uncoated band on the third anode.

' 2. An electron device comprising top and bottom insulating spacers and electrodes between the spacers forming a double triode, each triode comprising a cathode, control grid, and anode; said cathode projecting above thetop spacer and coated thereat with electron emissive material, each anode having a portion extending above the top spacer, a vertical plate above the spacer fastened to each extending portion of the anode, said plates being parallel to each other and positioned between the two cathodes, a third anode above the spacer parallel to and in between the two vertical plates and having faces opposite the vertical plates, and an electron sensitive phosphor on each of the said faces of the third anode, the

, material, each anode having a portion extending above the top spacer, a vertical plate above thespacer fastened to each extending .portion of the anode, said plates being parallel to each other and positioned between the two cathodes, a third anode above the spacer, parallel to and i in between the two vertical plates and having faces opposite the vertical plates, and an electron sensitive phosphor on each of said faces of the third anode, said faces on the third anode being inclined to each other and tapering toward the top, the phosphor being applied to each V face in the form of a strip leaving the upper portion of the face bare.

, References Cited in the file of this patent UNITED STATES PATENTS Kimball July 26, 1938 Hultquist Feb. 12, 1946 

